This proposal focuses on the study of electrochromatography as a viable analytical technique for separations of biomolecules. Electrochromatography is a hybrid technique that encompasses features of both chromatography and capillary electrophoresis. Separation is based on electrophoretic mobility and as well as interaction with a stationary phase. To make the technique more versatile, it is proposed that the surface within the capillary be increased so that a range of solute/stationary phase interactions (k') can be generated. The increase in surface area will be accomplished by two methods: the use of a roughening agent to produce radial extensions from the surface (whiskers) or by chemically bonding a polymer with a variety of functional groups to the capillary wall. Bonding of organic moieties to the whiskers or of the polymer to the capillary wall will be through hydrolytically stable silicon-carbon linkages. The two methods should generate a range of k' values so that it will be possible to optimize separations based on a combination of electrophoretic mobility and interaction with the stationary phase. The effects of residual silanols will be studied by tritium-labeling experiments. Eventually electrochromatography should develop into a separation technique for biomolecules that retains some of the important advantages of both HPLC and HPCE.